Endocrine disruption is a national and global concern that affects fish, wildlife, and human populations. Through interactions with neural, endocrine, and immune systems, endocrine disrupting compounds (EDCs) can influence growth, development, reproduction, disease, and mortality, with adverse outcomes for populations, communities, and ecosystems. Within the Chesapeake Bay, understanding the effects of EDCs on fish and wildlife populations has been identified as a priority to help inform natural resource management. Numerous studies have documented the effects chemicals have on endocrine function in fish and wildlife of the Chesapeake Bay watershed, documenting key EDCs and their endpoint effects on local fish assemblages. However, there has yet to be any work that documents the Bay-wide occurrence of known and/or potential EDC sources relative to observed or predicted receptor populations. One of the science questions outlined in the USGS Chesapeake Bay Watershed Endocrine Disruption Research Plan is to understand factors like land-use, land-use change, and climate that influence EDC sources and pathways as well as whether Best Management Practices (BMPs) like upgrades to Waste Water Treatment Plants (WWTPs) and manure application controls can help minimize the occurrence and effects of EDCs.

Methodology for Addressing the Issue
This project utilizes landscape features such as watershed characteristics, hydrology, BMPs, point and non-point sources of EDCs, and ecologically important habitats, for example, spawning and nursery grounds, to develop a relative risk assessment of EDC exposure for key indicator species at the Bay-scale. Information gained from this work can also be used to evaluate mitigation actions and help guide site-scale risk assessment models by prioritizing potential EDC sources, BMPs, and habitats. Locations of historic and ongoing EDC research efforts within the Bay are cataloged and assembled along with contaminant, habitat, BMP, and species distribution data in a geographic information system (GIS).

Future Steps Document less-reported non-point source EDC sources such as septic systems and fecal indicator bacteria in addition to established sources such as animal feeding operations and WWTPs.